Internal-combustion engine



y 1947. R. A. WEATHERUP INTERNAL COMBUSTION ENGINE Filed July 5, 1945 3 mun/(0w foeier ,4. MAW/ POP m M W Patented May 6, 1947 UNlTED STATES PATENT OFFICE INTERNAL-COMBUSTION ENGINE Robert A. Weatherup, Redlands, Calif.

Application July 5, 1945, Serial No. 603,307

Claims.

This invention relates to internal combustion engines and more particularly to a construction adapted to economize in fuel and improve running conditions generally.

In an internal combustion engine it is desirable to have a high compression ratio in the interest of fuel economy. In a gasoline engine the compression ratio is limited by the phenomena known as detonation. In a Diesel engine the compression ratio is limited by the excessively high peak pressures which accompany high compression ratios and high power output.

The present device is designed to permit higher compression ratios than are at present in use by providing a mechanism of a safety valve construction adapted to prevent excessively high pressures from developing Within the compression and combustion chamber.

Accordingly, it is one of the objects of the present invention to provide an internal combustion engine of either the gasoline or Diesel type tending towards fuel economy by the prevention of detonation in a gasoline engine and by the prevention of excessively high pressures in the combustion chamber of a Diesel engine.

A further object is to provide an engine of the above character of greater efiiciency and which will prevent excessively high peak pressures thus permitting lighter cylinder construction since the strength and weight of an engine cylinder are dependent upon the peak pressures at which it is designed to operate.

A further object is to provide a simple, practical and reliable engine operating at higher compression ratios and higher efficiencies than engines now in commercial use.

ther objects will be in part obvious from the annexed drawings and in part hereinafter indicated in connection therewith by the fbllowing description of this invention.

iis invention consists in the features of construction, combination of parts, and in the unique relation of the members and in the relative proportioning and disposition thereof, all as more completely outlined herein.

To enable others skilled in the art fully to comprehend the underlying features of this invention, that they may embody the same by the modifications in structure and relation contemplated by the invention, drawings depicting the preferred embodiments of the invention form a part of this disclosure, and in such drawings like characters of reference denote corresponding parts throughout the several views in which:

To enable others skilled in the art fully to comprehend the underlying features of this invention, reference is made to the accompanying drawing, wherein the figure illustrates diagrammatically in vertical cross-section an internal combustion engine cylinder and such associated parts as are necessary to understand the invention but omitting unnecessary parts. In this drawing there is shown only one cylinder, but it is to be understood that the invention is applicable to a multiple cylinder engine of any desired type, either gasoline or Diesel.

The piston in has an upwardly extending piston or guide rod 11 passing through a perforated guide plate l8 securely bolted as at 20 to the top of the cylinder. A nut 21 is threaded or otherwise secured to the top of the piston rod H for the purpose of preventing the piston 18 falling below the top of the compression chamber.

The upper part of the cylinder head provides a chamber 22 and communicates by pipe 23 with a reservoir 24 for hydraulic fluid, such as oil, wherein the oil is maintained under pressure by reason of the trap and air space 25. The lower part of this reservoir 2 5 communicates by pipe 25 with an oil sump 2B therebelow and in this pipe is located a pump 2'! and a regulator valve 28 having a bypass 39 leading back to the sump 26. Thus the pump 21 forces oil into the reservoir 24 under a predetermined degree of pressure. This pump is driven from any suitable source of power but would naturally be connected with the engine. If more oil' is supplied to the reservoir 24 and under greater pressure than de sired then the excess oil passes back through the pipe 39 to the sump 28. In a gasoline engine, regulator 28 is set at a pressure just under that pressure which would cause detonation. In a Diesel engine, regulator 28 is set at the desired peak pressure depending on the design and strength of the cylinders.

In this manner, oil under pressure is maintained in the top of the cylinder head and acts downwardly 0n the auxiliary piston It to hold the lower surface thereof in substantial alignment with the top wall of the combustion chamber and forms one of the boundary walls of such chamber and is movable with respect thereto in operation to enlarge said combustion chamber when such pressures exceed a certain amount determined by the adjustment of the regulator 28.

It is apparent that a hydraulic pressure is exerted on the top of the piston l6 thereby to hold it down in normal position and this piston will not move unless the pressure in the combustion chamber exceeds the hydraulic pressure above this piston. If the pressure in the combustion chamber does at any time exceed the hydraulic pressure above the piston 15, this piston will be forced upwardly thereby to enlarge the combustion chamber and prevent detonation if the invention is applied to a gasoline engine. On the other hand, in a Diesel engine, it will prevent excessively high peak pressure. As soon as pressure falls in the combustion chamber, then of course the piston 16 will return to its normal position. It will be noted particularly that there will be only a slight movement of the piston I6 at cruising speed or power thereby causing the engine to operate under such conditions at high compression ratios. At high power, there would be considerable movement of the piston I6 and the high pressures developed in the combustion chamber would lift this auxiilary piston and in so doing would reduce the peak pressures. The energy expended in raising this piston would be returned as auxiliary piston l6 returned to its power position and thus the device would improve fuel economy even at high powers and should also aid in scavenging.

A relatively small pipe 3i provides oil circulation from chamber 22 and from the top side of the auxiliary piston 5 back to the oil sump 26, thus providing a constant circulation of oil through the system disclosed and when the .englue is not running pipe 3! drains the upper part of the cylinders above the auxiliary piston l6 and thereby prevents any oil from leaking past the piston rings into the combustion chamber. Also this constant circulation of oil, the flow of which is restricted by the size of the pipe 3 I, aids materially in the cooling of the upper part of the cylinder,

From the above, it will be seen that the present invention provides a simple and practical mechanism which is entirely automatic in its operation and is not connected in any way or responsive to pressures within the manifold as are many similar inventions, but on the contrary it has a constant pressure exerted upon a movable wall portion of the combustion chamber and prevents the development of excessive pressures under any operating conditions. The invention is well adapted to accomplish among others, all of the objects and advantages herein set forth.

While it will be apparent that the illustrated embodiments of this invention herein disclosed are well calculated adequately to fulfill the objects and advantages primarily stated, it is to be understood that the invention is susceptible to variation, modifications and changes within the spirit and scope of the following claims.

I claim:

1. In a l internal combustion engine comprising a cylinder having a piston therein forming an expansible combustion chamber, and a movable wall member of large area having an inner side bounding a portion of said chamber and movable outwardly to increase the volume thereof; a controlling system for the wall member comprising fluid means for exerting on the outward side of said wall member a substantially fixed pressure, said means being arranged to yield at a rate sufficiently rapid to prevent pressure in the combustion chamber exceeding the said substantially fixed pressure exerted on the outward side of the wall member, and means for circulating said fluid means through a cooling system.

2. In an internal combustion engine comprising a cylinder having a piston therein forming an expansible combustion chamber, and a movable wall member of large area having an inner side bounding a portion of said chamber and movable outwardly to increase the volume thereof; a controlling system for the movable wall member comprising an enclosed body of fluid backing said member, means cooperating with said movable wall member for circulating said fluid through a cooling system, relief means for preventing rise of the pressure of the fluid above a predetermined maximum value, and means for constantly supplying fluid to said body at a pressure at least as great as the said predetermined maximum.

3. In an internal combustion engine comprising a cylinder having a piston therein to form an expansible combustion chamber and a movable wall member having an inner surface bounding a portion of said chamber and movable outwardly to increase the volume thereof; a controlling system for the said wall member comprising an enclosed body of fluid backing said member, a relief valve arranged to release fluid from the said body at a predetermined maximum pressure, and a pump arranged for constantly delivering fluid to said body at a pressure at least as great as said predetermined pressure.

4. In an internal combustion engine comprising a cylinder having a piston therein forming an expansible combustion chamber, and a movable wall surface having an inner side bounding a, portion of said chamber and movable outwardly to increase its volume; a controlling system for said movable wall member comprising an enclosed body of fluid backing said member, a pump constantly delivering fluid to said body at a pressure at least as great as a predetermined maximum pressure to which internal pressure of the combustion chamber is to be limited; a relief valve arranged to limit pressure of the body of fluid to the said predetermined maximum, and a cooling system for the movable wall member comprising a return passage for fluid from a point adjacent the wall member to the pump, said passage restricting flow of the fluid to be less than that delivered to the body by the pump.

5. In .an internal combustion engine comprising a cylinder having a piston therein forming an expansible combustion chamber, and a movable wall member having an inner side bounding a portion of said chamber and movable outwardly to increase the volume thereof; a controlling system for the wall member comprising an enclosed body of fluid backing the movable wall member and means maintaining the pressure of the body of fluid at a constant predetermined pressure comprising a sump, a pump delivering fluid from the sump to the enclosed body at a pressure at least as great as said predetermined pressure, a'by-pass from said body of fluid to the sump and a relief valve controlling said passage and arranged to permit flow of fluid through it at pressures above said predetermined maximum pressure.

ROBERT A. WEATHERUP.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,415,025 Folsom May 9, 1922 FOREIGN PATENTS Number Country Date 2,015 England Jan. 27, 1909 168,190 Germany Mar. 6, 1906 

